Monofacial PV Research Articles

Design of ground-mounted grid-connected photovoltaic system with bifacial modules using PVsyst software

Bifacial photovoltaic module has gained significant traction in recent years due to its higher irradiation capture capabilities with cost-effective technology. This paper presents the design, simulation, and techno-economic evaluation of a 45MW fixed-tilt ground-mounted grid-connected photovoltaic system with bifacial photovoltaic modules. The site is located in Sungai Petani, Kedah, Malaysia. The PVsyst 7.2 software was used to design the system by selecting the rating of PV module, inverter and tilt angle of PV modules. In addition, shading and loss calculation, as well as performance evaluation, were also conducted using the software. The simulation of the optimal geometrical parameters had shown an optimal tilt angle of 5°, the pitch of 5.5m and PV array installation height of 1.5m with an albedo value of 0.25. Besides, the performance of system with bifacial and monofacial modules were compared in terms of techno-economic performance indicators. The results showed that the bifacial PV system produces higher energy output with a lower levelized cost of electricity when compared to the system with monofacial PV modules.

Simulations of Luminescent Solar Concentrator Bifacial Photovoltaic Mosaic Devices Containing Four Different Organic Luminophores

In this article, various design configurations of luminescent solar concentrator photovoltaic (LSC-PV) devices have been simulated using Monte Carlo raytracing. These LSC PV devices are composed of mono-crystalline silicon solar cells and cubical poly (methyl methacrylate) lightguides, each containing one of the following dyes: Lumogen F Red 305, Lumogen F Orange 240, Perylene Green, or Perylene-diimide di-tert-butylphenyl, which results in different device colors. In these devices, mono-crystalline silicon bifacial PV cell are placed in between the vertical edge(s) of neighboring cubical lightguides whereas monofacial PV cells are positioned at the bottom of a lightguide. Each device is made out of five cubical 10 × 10 × 10 mm³ lightguides, meaning that the PV cells measure 10 × 10 mm². The main research goal of this article is to evaluate the optical and electrical performance of five of such configured LSC-PV devices. Hence, the spectral distribution of irradiance received by the edges and bottom of the devices has been simulated as well as the optical efficiency of these surfaces and the power conversion efficiency of each device. The theoretical results for power conversion efficiency are in the range of 13.3% to 18% under irradiance of 1000 W/m² and depend on the dyes applied. Hence, this article demonstrates the potential for energy generation by these colorful LSC-PV technologies, which we have called Mosaic devices.

Performance evaluation of bifacial solar PV modules under different climatic regions in Nigeria

Nigeria's annual solar radiation is estimated to be between 1400 and 2500 kWh/m2. This has made the use of solar energy to generate power in the country feasible. We investigated the performance of a bifacial solar PV system in Nigeria under various climatic regions in this study because bifacial PV modules are known to be location-dependent. The In-Plane solar radiation received by tilted monofacial and bifacial PV modules was calculated and compared using an analytical model. In all climatic regions, the bifacial PV system receives more in-plane solar irradiance. The systems were simulated on PVsyst to determine the energy yield, and the results show that under natural ground (vegetation and sand) of the various regions and optimization of the tilt angle, the bifacial PV system yielded more energy than the monofacial system. The bifacial gain varies depending on location, and system parameters must be optimized to improve the bifacial energy gain.

Modelling and Simulation of Bifacial PV Production Using Monofacial Electrical Models

In this paper, we investigate the use of monofacial PV models to simulate the production of bifacial PV systems over different albedos. Analytical and empirical models were evaluated using measured data obtained from three identical bifacial PV arrays: (1) with the backside covered by white plastic, (2) with normal albedo, and (3) with high albedo. The front-and rear-side irradiances were measured in order to integrate bifaciality of the modules into the models. The models showed good performance for non-real-time monitoring, especially under clear skies, and the analytical model was more accurate than the empirical model. The heatmap visualization technique was applied to six months of data in order to investigate the site conditions on the rear side of the modules as well as the accuracy of the models. The heatmap results of the rear- and front-sides irradiances showed that the installation conditions, such as the azimuth angles of the sun and the surrounding obstacles, had a strong impact on the energy received from the back of the modules. The heatmap results of the models validated the performance of the analytical model. The average daily errors for the analytical model were less than 1% and 3% for normal and high albedos, respectively.

Experimental observations in mismatch losses in monofacial and bifacial PV generators

AbstractMismatch losses ( ) in PV arrays have been experimentally investigated by observing the dispersion in the operating voltage of the individual modules under normal operating conditions, that is, with the inverter delivering energy to the grid, and by assuming that in the absence of mismatch, all the modules will have the same operating voltage which are equal to the observed average. For that, a quadratic relationship between relative power and relative voltage deviations derived from the power‐voltage curve of the modules is required. This has been carried out in two different PV generators: a 5.1 kWp with monofacial multicrystalline BSF modules installed in March 2013 and a 6.6 kWp with bifacial monocrystalline PERC modules, installed in May 2019. The respective coefficient of variation of the STC power is 1.6% and 0.3%. This decrease reflects the improvement between these two PV technologies and translates into a reduction in the component derived from intrinsic differences in the constitution of the module, from 0.09% to 0.01%, following theoretical considerations. The component due to the non‐uniformity of rear irradiance in the bifacial PV array is deduced by comparing its functioning with and without the rear side of the modules covered by opaque canvas and results in about 0.2–0.4%, which represents half of the total observed . The difference between these components and the total observed is attributed to differences in the module operating temperature. The aging of the monofacial PV array translates into an increase in at a ratio of 0.04% per year.

Assessment of the electrical and thermal performances of building integrated bifacial photovoltaic modules

In recent years the installation of photovoltaic modules integrated into the building envelope, namely Building Integrated Photovoltaic (BIPV) systems, are having an increasing diffusion. As they allow to locally produce renewable energy as well as replacing conventional construction elements providing savings in materials and construction times. Bifacial photovoltaic (bPV) modules could represent an interesting alternative to mono-facial PV modules even in the framework of building integration if the bi-faciality power production is harvested. In this study, a novel mathematical model, which allows evaluating the electrical and thermal energy balance of BIPV façades, is presented. The analysis is carried out through simulations in transitory conditions considering four alternatives configurations of building integrated active facades. In particular, non-ventilated (BIPV) and ventilated façade (V-BIPV) realized with mono facial panels, ventilated active façade realized with bifacial panel (V-BIbPV). This last configuration is also investigated adding a reflective surface on the rear side of the bPV panel (Vr-BIbPV).The results of the simulations, carried out assuming the weather data in Catania (Italy), indicate the glass-glass bifacial photovoltaic façade gives rise to an energy yield of about 5% more than the mono facial BIPV façade.

Sensitivity analysis of design parameters and power gain correlations of bi-facial solar PV system using response surface methodology

Sensitivity analysis of design parameters and power gain correlations of bi-facial solar PV system is presented in this paper. The main objectives are to study the effects of albedo, tilt angle and height from the ground on the performance of the system; determine the optimum operating conditions; and the development of new correlations for the annual energy yield and bifacial gain of bPV solar system. Three primarily significant installation parameters, albedo [10%, 50%, 90%], tilt angle [15°, 25°, 35°] and height [0.5 m, 1 m, 1.5 m] are investigated with PVSYST for bifacial and mono-facial PV modules. The response surface methodology (RSM) based optimization method is used to determine the optimum conditions and the interaction of these three parameters on the performance of bPV solar system. New quadratic equations or correlations are introduced to estimate the annual energy yield and bifacial gain of bPV. The results show that the albedo is the most significant parameter between tilt angle and height. The increase in albedo factor and height of bPV modules from ground increase the energy yield. In this study, the optimum tilt angle of bPV is found to be 35°for higher albedo and elevation of bPV from the ground as compared to 25° of mPV. An average daily bifacial gain of 35.68% can be achieved in clear sunny day with 90% albedo, tilt angle of 35° and at height of 1.5 m. The maximum specific productions of 192.4 kWh/kWp and 160.6 kWh/kWp are observed in May for bPV and mPV, respectively while the maximum bifacial gain of 21.93% is found in July.

Analysis of water environment on the performances of floating photovoltaic plants

There is an increasing interest in Floating PV (FPV) plants thanks to their advantages compared with ground and rooftop PV systems, mainly related to very limited land use, evaporation reduction, and improvement of the energy performance. The PV modules installed on water surfaces have a natural cooling due to the microclimate in which they operate, which reduces thermal power losses. Furthermore, they can be equipped with simple and effective forced active water cooling systems which further improve FPVs performance. The objective of this study is to develop and validate mathematical models capable of estimating the performance of bifacial and monofacial PV modules installed on water surfaces. Starting from the energy balances of the PV modules, different scenarios are simulated, such as mono and bifacial systems installed on the rooftop, mono, and bifacial FPV systems in presence of natural (or passive) and forced (or active) cooling. The models are validated against experimental data acquired in FPV systems installed in the Enel Innovation Lab by Enel Green Power, Catania (Italy). The obtained results show an energy gain due to bifaciality of 5.24%. The passive cooling in the FPV increases the energy collected by 3% (maximum obtainable of 6.4%) and 2.6% for the bifacial and monofacial technology respectively. Active cooling in FPVs increases the collected energy by 9.7% (maximum achievable of 13.5%) and 9.5% for the bifacial and monofacial respectively.

Performance assessment of conceptual bifacial solar PV system in varying albedo conditions

There is a rapidly growing interest in bifacial module based solar PV. Unlike conventional solar PV modules, the energy output of the bifacial PV module is affected by the reflectance of the ground surface (albedo). This paper aims to assess the performance of conceptual bifacial solar PV systems in varying albedo conditions. Besides, the comparison of energy generation between monofacial and bifacial solar PV system is carried out. In this regard, four sites on an educational campus having different albedo factor is chosen. The annual energy output, specific yield, and performance ratio are estimated using PVSyst simulation software. The energy output of 164.5 MWh/year is predicted for the minimum albedo factor of 0.15. While 175.8 MWh/year is expected for the maximum albedo factor of 0.85. The specific yield for Case 5 (bifacial) is 10.58 % higher than that estimated for Case 1 (monofacial). Based on annual energy generation, the site of Case 4 is the best location for the solar PV system among the studied cases. It is concluded that setting up of bifacial solar PV module on the ground surface with a high value of albedo factor is suitable to maximize energy generation.

Design, simulation and analysis of monofacial solar pv panel based energy system for university residence: a case study

This paper proposes a design and software simulation of monofacial solar photovoltaic panel based energy harvesting system for university residence. As the site of the proposed system, the rooftop of North Hall of Residence of the Islamic University of Technology (IUT) is considered. The 3D model of the system is demonstrated by utilizing PVSOL software. The monthly energy production is obtained by performing the simulation in three software named PVSOL, PVsyst, and System Advisor Model (SAM). However, the monthly consumption of the residence is tabulated and graphical presentation is depicted. Hence, the energy flow diagram is illustrated showing that the proposed PV system can contribute 18.4% in the annual demand of the site. The performance of each of the software is evaluated and deviation analysis is performed so that more insight can be achieved in terms of harvesting solar energy. Hence, a cost-effective and self-reliant solar energy model for the rooftop of a university residence is proposed by utilizing monofacial solar PV panels.

Monofacial and Bifacial Micro PV Installation as Element of Energy Transition—The Case of Poland

The several government subsidies available in Poland contributed to an increased interest in PV installations. Installed PV capacity increased from 100 MW in 2016 up to 2682.7 MW in July 2020. In 2019 alone, 104,000 microinstallations (up to 50 kWp) were installed in Poland. The paper determines the energy gain and the associated reduction of CO2 emissions for two types of solar installation located in Poland. The monofacial solar modules with a power of 5.04 kWp (located in Leki) and bifacial solar modules with a power of 6.1 kWp (located in Bydgoszcz). Both installations use mono-crystalline Si-based 1st generation PV cells. With comparable insolation, a bifacial installation produces approx. 10% (for high insolation) to 28% (for low insolation) more energy than a monofacial PV installation. Avoided annual CO2 emission in relation to the installation capacity ranges from 0.58 to 0.64 Mg/kWp for monofacial and from 0.68 to 0.74 Mg/kWp for bifacial and is on average approx. 16% higher for bifacial installations. Cost-benefit analyses were made. For different electricity prices, the NPV for monofacial and bifacial was determined.

Innovative floating bifacial photovoltaic solutions for inland water areas

AbstractPhotovoltaic (PV) technology has the potential to be integrated on many surfaces in various environments, even on water. Modeling, design, and realization of a floating PV system have more challenges than conventional rooftop or freestanding PV system. In this work, we introduce two innovative concepts for floating bifacial PV systems, describing their modeling, design, and performance monitoring. The developed concepts are retractable and enable maximum energy production through tracking the Sun. Various floating PV systems (monofacial, bifacial with and without reflectors) with different tilts and tracking capabilities are installed on a Dutch pond and are being monitored. Results of the thermal study showed that partially soaking the frame of PV modules into water does not bring a considerable additional yield (+0.17%) and revealed that floating PV modules experience higher temperature special variance compared with land‐based systems. Observations showed that the birds' presence has a severe effect on floating PV performance in the short term. Electrical yield investigation concluded that due to low albedo of inland water areas (~6.5%), bifacial PV systems must have reflectors. One‐year monitoring showed that a bifacial PV system with reflector and horizontal tracking delivers ~17.3% more specific yield (up to 29% in a clear‐sky month) compared with a monofacial PV system installed on land. Ecological monitoring showed no discernable impacts on the water quality in weekly samplings but did show significant impacts on the aquatic plant biomass and periods of low oxygen concentrations.

Photovoltaic thermal (PVT) air collector with monofacial and bifacial solar cells: a review

Photovoltaic thermal (PVT) collectors directly convert solar radiation into electrical and thermal energy. A PVT collector combines the functions of a PV panel and a flat plate solar collector. The development of PVT air collectors is a very promising research area. At present, PVT air collectors are used in solar drying and solar air heaters. On the basis of existing literature, most PVT air collectors were built by using monofacial PV modules. The bifacial PV modules had two active surfaces that could capture solar radiation with its front and rear surfaces. Additional sunlight absorption through both surfaces resulted in an enhanced electrical power generation compared with the conventional monofacial PV. Therefore, bifacial PVT was considered to be useful and attractive due to its potential of enhancing overall system performances, including energy and exergy efficiencies. Findings of this review indicated that PVT air collector with bifacial solar cell produced a larger amount of electrical energy, which was approximately 40% higher than a monofacial PVT. The energy and exergy efficiencies of PVT air collector with monofacial solar cells range from 27% to 94% and from 4% to 18%, respectively. For bifacial PVT, the energy and exergy efficiencies of PVT air collector range from 28% to 67% and from 8.2% to 8.4%, respectively.

Extended model for irradiation suitable for large bifacial PV power plants

This paper presents a model for the calculation of irradiation for large bifacial PV power plants. The represented model, convenient for hourly meteorological data, enables calculations of typical daily and annual electricity production (AEP) of PV power plants. The results of comparisons of the proposed model that takes into account the fact that not all the diffuse irradiation incident on the surface between PV rows and the existing irradiation models justify proposed irradiation model. The significance of the proposed model is highlighted for bifacial PV power plants due to significant share of reflected irradiation component in production bifacial PV power plants. Depending on a reflection coefficient of the surface between PV rows and the distance between PV rows, a deflection of the production based on the proposed and existing model of irradiation can reach even more than 20%. For the same reflection coefficient of the surface between PV power plants, the production of bifacial PV power plant is bigger even for more than 20%, and LCOE smaller for 8.7% in comparison with monofacial PV power plants. Taking into account the power plant owners’ interests in profit maximization, it has been shown that it is economically justifiable to mount reflectors between PV rows in bifacial PV power plants in case when the reflection coefficient is above 0.6 provided that its price does not exceed 7.4 €/m2.

양면수광형 태양광 모듈의 운전 알고리즘 적용에 따른 발전성능 분석

The bifacial PV module can be used in various industrial fields for solar power generation as a low cost and high-efficiency PV because it is capable of power generation by both front and rear side and can be made using the conventional manufacturing technology. In related articles, it is reported that the bifacial PV module has 5∼20% better performance than the monofacial PV. However, For effective power generation by rear side of bifacial PV, it is necessary to consider the environmental factors such as the latitude, the local diffuse fraction and the albedo. In this paper, We modeled a bifacial PV with TRNSYS simulation tool and analyzed the bifacial gain in Seoul, Daejeon, Jeju according to 8 installation and operation condition by year, month and days. Based on the results, We suggested an operating method that can improve the power generation performance of the bifacial PV module.

Simulating the energy yield of a bifacial photovoltaic power plant

Bifacial photovoltaics (bifacial PV) offer higher energy yields as compared to monofacial PV. The development of appropriate models for simulating the energy yield of bifacial PV power plants is a major topic in both research and industry. In particular, the adequate calculation of the energy yield from ground-reflected irradiance (GRI) is challenging. The purpose of this work is to investigate the currently available energy yield models and suggest areas for improvement. A new model with the proposed enhancements is used to investigate the behaviour of bifacial PV power plants in more detail. The model calculates the absorbed irradiation originating from eight irradiance contributions for the front and rear of each cell string: DNI, DHI, GRI from DHI (GRIDHI) and GRI from DNI (GRIDNI). The model was tested using a defined case study power plant. The breakdown of absorbed irradiation (subscript “ab”) into its contributions revealed that while in summer months GRIDNI-ab-rear is significantly larger than GRIDHI-ab-rear, both are roughly the same in winter months. Furthermore, for the calculation of GRI the common simplification of infinitely long module rows was avoided by implementing an algorithm for the view factor calculation for a three-dimensional space. This procedure allowed for the assessment of impact of the ground size on the annual energy yield. In a sensitivity analysis, it has been shown that the extension of the relevant ground area resulted in an asymptotical increase of the energy yield. Additionally, the impact of ground shadows on the power plant’s performance was quantified. The presence of ground shadows reduced the annual electricity generation by almost 4%, compared to a hypothetical scenario where no ground shadows existed. Finally, five different ground surfaces and the resulting bifacial gains were analysed. The results show that while dry asphalt (12% reflectivity) gave less than 6% of bifacial gain related to generated electricity (BGel), the use of a white membrane (70%) would result in 29% of BGel.

Photovoltaics literature survey (no. 149)

Photovoltaics literature survey (no. 149)

Monofacial vs bifacial Si-based PV modules: Which one is more cost-effective?

The present work studies the features of photovoltaic systems (PV) formed either by monofacial or bifacial crystalline p-type Si-based solar modules. To determine which module technology would be more favorable worldwide, a total of 55 locations around the globe are analyzed considering their weather profiles, market situation, and module electrical performance for 1 MWp systems. Levelized cost of electricity (LCOE) of the system has been used to decide which technology is more cost-effective. This is obtained for installations which allow any module orientation (AMO) or vertical module orientation (VMO). The results reveal that for latitudes above 40°, bifacial AMO designs are in general more cost-effective than monofacial AMO systems. This tendency is reversed, however, for latitudes below 40° with low albedo values. Nevertheless, if the albedo value is kept to a minimum between 0.12 and 0.30 (depending on the location), bifacial AMO designs can become more cost-effective. When comparing monofacial AMO against bifacial VMO, the latter is more cost-effective only for locations close to the poles, i.e., latitudes higher than 65°. Nonetheless, bifacial VMO designs could even reach lower LCOE values than the ones from monofacial AMO systems at latitudes below 65° if the albedo value is maintained to a minimum between 0.29 and 0.57 (depending on the location). This work will be useful not only to the scientific community, but also to PV installation companies to properly select the most adequate technology, and to optimize the installation design for particular projects.

Design Elements and Electrical Performance of a Bifacial BIPV Module

Bifacial BIPV systems have great potential when applied to buildings given their use of a glass-to-glass structure. However, the performance of bifacial solar cells depends on a variety of design factors. Therefore, in order to apply bifacial solar cells to buildings, a bifacial PV module performance analysis should be carried out, including consideration of the various design elements and reflecting a wide range of installation conditions. This study focuses on the performance of a bifacial BIPV module applied to a building envelope. The results here show that the design elements of reflectivity and the transparent space ratio have the greatest impact on performance levels. The distance between the module and the wall had less of an impact on performance. The bifacial BIPV module produced output up to 30% greater than the output of monofacial PV modules, depending on the design elements. Bifacial BIPV modules themselves should have transparent space ratios of at least 30%. When a dark color is used on the external wall with reflectivity of 50% or less, bifacial BIPV modules with transparent space ratios of 40% and above should be used. In order to achieve higher performance through the installation of bifacial BIPV modules, design conditions which facilitate reflectivity exceeding 50% and a transparent space ratio which exceeds 30% must be met.

Performance of Bi-Facial PV Modules in Urban Settlements in Tropical Regions

This paper studies the performance of bifacial Heterojunction with Intrinsic Thin-layer (HIT) PV modules through a one-year experiment in Singapore. Two 1.2kWp (front side)/0.84kWp (rear side) PV systems were installed vertically, facing the N-S and E-W directions respectively. The operational data of two systems were monitored and collected to analyze their performance under different weather conditions. This paper will presentthe change of irradiation, energy yield and the AC energy output of the bifacial PV systems. The results help to understand the impacts of system installation on the energy yield of vertically-installedbifacial HIT PV systems, to find out its advantages in applications over monofacial PV modules and to explore the potential of bifacial PV modules in tropical regions, especially in urban areas like Singapore.